Fault Detection in Switched Current Circuits Using Built-in Transient Current Sensors

Abstract

Switched current (SI) circuits use analogue memory cells as building blocks. In these cells, like in most analogue circuits, there are hard-to-detect faults with conventional test methods. A test approach based on a built-in dynamic current sensor (BIDCS), whose detection method weights the highest frequency components of the dynamic supply current of the circuit under test, makes possible the detection of these faults, taking into account the changes in the slope of the dynamic supply current induced by the fault. A study of the influence of these faults in neighbouring cells helps to minimize the number of BICS needed in SI circuits as is shown in two algorithmic analogue-to-digital converters.